Cutting 200 calories daily plus aerobic exercise may improve aortic stiffness in older adults
Intensive caloric restriction may not be necessary to improve aortic stiffness in older adults with obesity who are also getting daily aerobic exercise, according to research published in Circulation.
Tina E. Brinkley, PhD, associate professor of gerontology and geriatric medicine at the Sticht Center for Healthy Aging and Alzheimer’s Prevention at Wake Forest School of Medicine, and colleagues found that cutting as few as 200 calories per day in addition to aerobic exercise may be enough to increase aortic distensibility and decrease pulse wave velocity.
“This is the first study to assess the effects of aerobic exercise training with and without reducing calories on aortic stiffness, which was measured via cardiovascular magnetic resonance imaging (CMR) to obtain detailed images of the aorta,” Brinkley said in a press release. “We sought to determine whether adding caloric restriction for weight loss would lead to greater improvements in vascular health compared to aerobic exercise alone in older adults with obesity.”
For this study, researchers enrolled 160 participants (mean age, 69 years; 74% women; 73% white) and randomly assigned them to one of three groups for 20 weeks: aerobic exercise training only, aerobic exercise training plus moderate caloric restriction (subtracting 250 calories daily) or aerobic exercise training plus more intensive caloric restriction (subtracting 600 calories daily). All participants had a BMI between 30 kg/m2 and 45 kg/m2. Pulse wave velocity, aortic distensibility and other measures of aortic structure and function were evaluated using cardiac MRI.
Researchers reported that weight loss in the aerobic exercise plus moderate caloric restriction (8 kg; 95% CI, 9.17 to 6.87) and aerobic exercise training plus intensive caloric restriction (8.98 kg; 95% CI, 10.23 to 7.73) groups was greater compared with weight loss achieved in the aerobic exercise training-only group (1.66 kg; 95% CI, 2.94 to 0.38; P for both < .017).
In the aerobic exercise training plus moderate caloric restriction group, Brinkley and colleagues observed a significant treatment effect for descending aorta distensibility (P = .008) and strain (P = .004) and aortic arch pulse wave velocity (P = .01). This group also experienced a 21% increase in distensibility (P = .016) and an 8% decrease in pulse wave velocity (P = .058) associated with the intervention.
The researchers reported no changes in the measures of aortic stiffness or any other measure of aortic structure or function in the aerobic exercise training-only or aerobic exercise training plus more intensive caloric restriction groups.
Intensive caloric restriction questioned
“Our findings indicate that lifestyle changes designed to increase aerobic activity and moderately decrease daily calorie intake may help to reduce aortic stiffness and improve overall vascular health,” Brinkley said in the release. “However, we were surprised to find that the group that reduced their calorie intake the most did not have any improvements in aortic stiffness, even though they had similar decreases in body weight and blood pressure as the participants with moderate calorie restriction.
“These results suggest that combining exercise with modest calorie restriction — as opposed to more intensive calorie restriction or no-calorie restriction — likely maximizes the benefits on vascular health, while also optimizing weight loss and improvements in body composition and body fat distribution,” Brinkley said in the release. “The finding that higher-intensity calorie restriction may not be necessary or advised has important implications for weight loss recommendations to improve cardiovascular disease risk in older adults with obesity.”
Editor's Note: This article was updated on Aug. 2, 2021 to change the headline and second paragraph from 250 to 200 after the American Heart Association issued a correction to its press release about this study.